Instruments used by surgeons during surgical procedures are commonly laid out on a moveable tray table called a "Mayo stand". A Mayo Stand includes a tray on which instruments to be used during surgery are placed, a vertical leg from which the tray is cantilevered, and a base, usually including casters, which supports the vertical leg. In order to insure sterility, just prior to surgery, the tray and the vertical leg of the stand are ordinarily covered with a disposable sterile bag made of plastic tubing. Since the tray is horizontal and the leg is vertical, the plastic tubing must be made relatively large so that it can easily be slipped around the corner where the tray and the leg join.
A typical Mayo Stand tray may be 13 inches wide by 19 inches long and supported at one end (at table height) by one or two vertical members. The plastic tubing commonly used to make a cover for such a stand has a circumference of about 46 to 48 inches. That is, when flattened and made into a bag, the tubing is 23 to 24 inches wide. The extra 10 or so inches in width are required to assure that there will be no binding as the cover is installed.
The extra material, while needed for ease in installation, also creates a problem. The problem is that the portion of the cover which covers the tray tends to not center on the tray; it rather tends to twist and create folds in the area of the tray where the instruments are to be placed. There is also the risk that the cover might shift during surgery if it is brushed against, with disastrous results.
It is therefore an object of this invention to provide a Mayo Stand cover which is self centering on the tray, and which provides a flat smooth, positionally stable, surface on which to place surgical instruments.